Encoder module for a revolute joint, revolute joint, robot arm and robot

Abstract

Disclosed are an encoder module for a rotary joint, a rotary joint, a mechanical arm and a robot. The encoder module is installed in a rotary joint comprising a driving device having radially spaced inner and outer shafts, and comprises: a first connecting shaft, a first end of which is connected to an end of the outer shaft; a second connecting shaft, a first end of which is fixedly connected to the inner shaft; a first magnetic disk assembly fixed to the first connecting shaft; a second magnetic disk assembly fixed to the second connecting shaft; a first sensor assembly arranged adjacent to the first magnetic disk assembly; and a second sensor assembly arranged adjacent to the second magnetic disk assembly, wherein a disk surface of the first magnetic disk assembly and a disk surface of the second magnetic disk assembly are coplanar and radially spaced apart by at least a predetermined distance. In the rotary joint according to the application, the encoder module not only saves axial space of the joint, but also facilitates gap adjustment between the sensors and the magnetic disks, and the installation and removal of the encoder module is efficient.

Description

Technical Field

[0001] This application relates to the field of robotics, and more specifically, to an encoder module for a rotary joint, a rotary joint having the encoder module, and a robotic arm and robot having the rotary joint. Background Technology

[0002] In general, robots with robotic arms rely on joints to control the relative movement between the components of the robotic arm. Joints are typically divided into rotary joints and translational joints (also known as kinetic joints). Rotary joints utilize a drive mechanism to connect two components for rotation, causing relative movement between them. To precisely control the movement and position of the robotic arm, it is necessary to accurately measure the rotational speeds of the two output shafts of the drive mechanism and adjust the speed of each output shaft based on the measured speeds.

[0003] Encoders are typically used to measure the rotational speed of the two output shafts of a drive unit. An encoder is a device that converts a signal into a sine wave using magnetic or optical measurement principles. Magnetic encoders can achieve resolutions as low as 1 micrometer. They are resistant to vibration, dust, oil, moisture, and salt spray, and are more robust and durable than optical encoders. Therefore, magnetic encoders are widely used in robotics where precise control of motion is required.

[0004] A magnetic encoder comprises a magnetic disk, a sensor, and a conditioning circuit. The disk is magnetized, with numerous magnetic poles distributed around its circumference, adjacent poles having opposite polarities. The sensor detects changes in the magnetic field as the disk rotates and converts this information into a sine wave. The sensor can be a Hall effect device that senses changes in voltage or a magnetoresistive device that senses changes in the magnetic field. The conditioning circuit multiplies, divides, or interpolates the signal to produce the desired output.

[0005] In the robot's joints, the two output shafts of the drive unit are typically located on either side of the drive unit, and correspondingly, two sets of magnetic encoder modules are also located on either side of the drive unit. Each magnetic encoder module has a disk and a PCB circuit board with a sensor chip, wherein the disk is fixed to the output shaft, and the corresponding PCB circuit board is mounted to remain fixed relative to the drive unit. Summary of the Invention

[0006] According to a first aspect of this application, an encoder module with a rotary joint that is easy to install and remove is provided, a rotary joint having the encoder module structure, and a robotic arm and robot having the rotary joint are provided.

[0007] According to at least one embodiment of this application, an encoder module for a rotary joint is provided, the rotary joint including a drive device having an inner shaft extending toward the same side and an outer shaft surrounding the inner shaft and radially spaced from the inner shaft, the encoder module including: a first connecting shaft having a first end and a second end, the first end of the first connecting shaft being used to connect to the end of the outer shaft; a second connecting shaft having a first end and a second end, the first end of the second connecting shaft being used to be fixedly connected to the inner shaft; a first disk assembly fixed to the first connecting shaft; a second disk assembly fixed to the second connecting shaft; a first sensor assembly arranged adjacent to the first disk assembly; a second sensor assembly arranged adjacent to the second disk assembly, wherein the disk surfaces of the first disk assembly and the disk surfaces of the second disk assembly are arranged coplanarly and radially separated by at least a predetermined distance.

[0008] The encoder module may also include a bearing installed between the first connecting shaft and the second connecting shaft.

[0009] The first connecting shaft is a hollow shaft and a first bearing positioning shoulder may be formed on its inner circumferential surface, and / or a second bearing positioning shoulder may be formed on the outer circumferential surface of the second connecting shaft.

[0010] A first connecting positioning shoulder may be formed on the inner or outer circumferential surface of the first end of the first connecting shaft for positioning the first connecting shaft relative to the outer shaft.

[0011] An additional module positioning shoulder may be formed on the outer peripheral surface of the first connecting shaft.

[0012] A second connecting positioning shoulder may be formed on the outer peripheral surface of the second connecting shaft or on the end surface of the first end, for positioning the second connecting shaft relative to the inner shaft.

[0013] The second connecting shaft is a hollow shaft, and a second connecting positioning shoulder and / or a disassembly auxiliary shoulder may be formed on the inner circumferential surface. The second connecting positioning shoulder is used to position the second connecting shaft relative to the inner shaft, and the disassembly auxiliary shoulder is used to separate the second connecting shaft from the inner shaft.

[0014] The end surface of the second end of the first connecting shaft is flush with the outer end surface of the bearing, and the end surface of the second end of the second connecting shaft is flush with the disk surface of the first disk assembly and the disk surface of the second disk assembly.

[0015] The bearing can be bonded to at least one of the first connecting shaft and the second connecting shaft by means of an adhesive.

[0016] The bearing may be a deep groove ball bearing, and the inner ring of the bearing may be bonded to the second connecting shaft with an adhesive.

[0017] The encoder module may further include a PCB circuit board on which the first sensor assembly and the second sensor assembly are mounted, wherein the PCB circuit board is parallel to and spaced apart from the disk surfaces of the first disk assembly and the second disk assembly.

[0018] The first disk assembly may include a first disk and a first mounting bracket supporting the first disk, the first mounting bracket being mounted on the second end of the first connecting shaft.

[0019] The second disk assembly may include a second disk and a second mounting bracket supporting the second disk, the second mounting bracket being mounted on the second end of the second connecting shaft.

[0020] The first mounting bracket is spaced apart from the first mounting shaft in both the axial and radial directions, wherein the first mounting bracket and the first connecting shaft are formed separately or integrally, and the second mounting bracket and the second connecting shaft are formed separately or integrally.

[0021] The outer and / or inner rings of the first disk can be fixed to the first mounting bracket, and the outer and / or inner rings of the second disk can be fixed to the second mounting bracket.

[0022] According to some embodiments of this application, a rotary joint for a robot is provided, which has a joint housing, the aforementioned drive device, and the aforementioned encoder module for the rotary joint.

[0023] The drive device may include a motor and a transmission device driven by the motor, wherein the motor can drive one of the inner shaft and the outer shaft, and the transmission device can drive the other of the outer shaft and the inner shaft.

[0024] The drive unit can be installed inside the joint housing, and the encoder module can extend a predetermined length relative to one end of the joint housing.

[0025] The rotating joint may also include a control device for adjusting the operation of the drive device based on signals output by the first sensor assembly and the second sensor assembly.

[0026] According to some embodiments of this application, a robotic arm for a robot is provided, which includes at least one rotary joint for a robot as described above.

[0027] According to some embodiments of this application, a robot is provided, including at least one rotary joint for the robot as described above.

[0028] In the encoder module, rotary joint, robotic arm and robot for rotary joint according to the embodiments of this application, the encoder module not only saves the axial space of the joint, but also makes the gap between the sensor and the disk easy and quick to adjust, and the installation and disassembly of the encoder module are highly efficient. Attached Figure Description

[0029] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application. In order to more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic partial cross-sectional view illustrating the structure of the encoder module in the rotary joint according to an embodiment of this application;

[0031] Figure 2 This is a schematic partial cross-sectional view illustrating the structure and mounting method of the disk assembly of the encoder module in a rotary joint according to an embodiment of this application;

[0032] Figure 3 This schematically illustrates a partial cross-sectional view of the mounting structure of the two disk assemblies of the encoder module in a rotary joint according to an embodiment of this application;

[0033] Figure 4 This is a perspective view schematically illustrating the combined structure of the disk assembly and connecting shaft in an encoder module according to an embodiment of this application. Detailed Implementation

[0034] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0035] The following will refer to the appendix. Figure 1-4 Detailed description of specific embodiments according to this application.

[0036] like Figures 1 to 4As shown, a rotary joint according to one embodiment of this application includes a drive unit (not shown), a joint housing 20, and an encoder assembly 30. The drive unit is fixedly mounted in the joint housing 20 and has two shafts extending toward the same side of the drive unit and rotating about the same axis, namely an outer shaft 11 and an inner shaft 12. The outer shaft 11 is a hollow shaft that surrounds the inner shaft 12 and is radially spaced from the inner shaft. Thus, the inner shafts 11 and 12 rotate independently of each other.

[0037] The encoder assembly 30 includes a disk assembly and a sensor assembly, wherein the sensor assembly can be mounted on a PCB circuit board 50, which can be mounted perpendicular to the output axis of the drive device. Specifically, the disk assembly includes a first disk assembly 31 that rotates synchronously with the outer shaft 11 and a second disk assembly 32 that rotates synchronously with the inner shaft 12. The sensor assembly includes a first sensor assembly for detecting changes in the magnetic field generated by the rotation of the first disk assembly 31, and a second sensor assembly for detecting changes in the magnetic field generated by the rotation of the second disk assembly 32.

[0038] The PCB circuit board 50 is mounted relative to the drive device via a connecting assembly 40, for example, fixed to the joint housing 20. In one embodiment, the PCB circuit board is mounted parallel to and spaced apart from the disks of the disk assembly, for example, connected to one end of the joint housing 20 while being spaced a predetermined distance from said end of the joint housing 20. Although the first sensor assembly and the second sensor assembly can be mounted on different circuit boards, it is advocated in this application to mount them on the same PCB circuit board 50, which is beneficial for saving PCB circuit board mounting space and simplifying installation.

[0039] The sensor assembly can be a sensor chipset, such as a Hall effect sensor chipset or a giant magnetoresistive (GMR) chipset. Signal processing circuitry is integrated into the chip within each sensor assembly. This signal processing circuitry processes the electrical signals sensed by the sensors in the sensor assembly to output a rotational speed-related digital signal to a control device of at least one of the following: a joint, a robotic arm with that joint, or a robot with that joint. The control device can adjust the output rotational speed of the drive mechanism according to a predetermined program based on the received digital signal, or correct the output rotational speed of the drive mechanism based on an error generated. Here, the error refers to the difference between the measured rotational speed and the desired rotational speed.

[0040] The drive unit is mounted and fixed in the joint housing 20, and can be configured in various ways, such as a dual-motor, dual-axis motor, or motor and transmission system. The motor and transmission system includes a motor and a transmission device, which can be driven by the motor and can be a reducer, gearbox, or speed-up device. Figure 1As shown, the drive unit extends two concentric rotating shafts toward one side, namely, an outer shaft 11 and an inner shaft 12. For example, the outer shaft 11 is driven to rotate by a motor, and the inner shaft 12 is driven to rotate by a transmission device. The outer shaft 11 can be the drive shaft of a rotary joint; for example, the outer shaft 11 can be directly the motor output shaft of the rotary joint. The inner shaft 12 can be the output shaft of the rotary joint, connected to the output shaft of the rotary joint, or as part of the output shaft of the rotary joint. The outer shaft 11 surrounds the inner shaft 12 and is radially spaced from the inner shaft 12, so that the outer shaft 11 and the inner shaft 12 can rotate independently of each other.

[0041] In one embodiment, the length of the outer shaft 11 extending from the drive device is shorter than the length of the inner shaft 12 extending from the drive device, that is, as Figure 1 and Figure 2 As shown, the outer shaft 11 is a hollow shaft, and the inner shaft 12 extends a certain length from the end of the hollow outer shaft 11. Clearly, as... Figure 1 and Figure 2 As shown, the inner shaft 12 can also be designed as a hollow shaft, which not only reduces the weight of the inner shaft but also allows it to be used as a guide shaft for rotating joints. If necessary, the inner shaft 12 can also be designed as a solid shaft, or its end can be designed so that it does not extend beyond the end of the outer shaft 11.

[0042] The end of the outer shaft 11 is connected to the first connecting shaft 61, and the end of the inner shaft 12 is connected to the second connecting shaft 62. The first connecting shaft 61 is used to install the first disk assembly 31, and the second connecting shaft 62 is used to install the second disk assembly 32.

[0043] The following will combine Figures 1 to 4 The mounting structure for mounting the encoder assembly 30 to monitor the drive shaft and output shaft of the rotary joint is described in detail using a first connecting shaft 61 and a second connecting shaft 62.

[0044] The first connecting shaft 61 is a hollow shaft, and the second connecting shaft 62 is also a hollow shaft. At any position in the axial direction, the outer diameter of the second connecting shaft 62 is smaller than the inner diameter of the first connecting shaft 61. That is, the first connecting shaft 61 is located radially outside the second connecting shaft 62. In other words, the second connecting shaft 62 is located in the hollow part of the first connecting shaft 61 and is surrounded by the hollow first connecting shaft 61, with the two separated radially.

[0045] The first connecting shaft 61 has a first end fixedly connected to the end of the outer shaft 11 and a second end for mounting the first disk assembly 31. The second connecting shaft 62 has a first end fixedly connected to the end of the inner shaft 12 and a second end for mounting the second disk assembly 32. The first connecting shaft 61 and the outer shaft 11 can be connected by an interference fit, and the second connecting shaft 62 and the inner shaft 12 can also be connected by an interference fit. In addition, if necessary, adhesive can be applied between the first connecting shaft 61 and the outer shaft 11 and / or between the second connecting shaft 62 and the inner shaft 12.

[0046] Thus, the first connecting shaft 61, the outer shaft 11, and the first disk assembly 31 rotate synchronously, and the rotational speed of the first disk assembly 31 is the rotational speed of the drive shaft of the rotating joint; the second connecting shaft 62, the inner shaft 12, and the second disk assembly 32 rotate synchronously, and the rotational speed of the second disk assembly 32 is the rotational speed of the output shaft of the rotating joint.

[0047] A bearing 70, such as a deep groove ball bearing, is mounted between a first connecting shaft 61 and a second connecting shaft 62. The outer ring of the bearing 70 contacts the inner surface of the first connecting shaft 61, and the inner ring of the bearing 70 contacts the outer surface of the second connecting shaft 62. Preferably, the bearing 70 is mounted at the second end of the first connecting shaft 61, with one end surface flush with the second end surface of the first connecting shaft 61, and the other end abutting against a bearing locating shoulder 623 formed on the outer surface of the second connecting shaft 62. A bearing locating shoulder 613 may also be formed on the inner surface of the first connecting shaft 61. To ensure a secure connection between the bearing 70 and the first connecting shaft 61 and the second connecting shaft 62, an adhesive, such as 609 glue, may be applied between the first connecting shaft 61 and the outer ring of the bearing, and between the second connecting shaft 62 and the inner ring of the bearing 70. To ensure a secure installation, an interference fit connection is suitable for the connection between the bearing 70 and the first connecting shaft 61 and the second connecting shaft 62.

[0048] In addition, such as Figure 1 and Figure 2 As shown, a first connecting positioning shoulder 611 is formed on the inner circumferential surface of the first end of the first connecting shaft 61 to position the first connecting shaft 61 relative to the outer shaft 11. A second connecting positioning shoulder 621 is formed on the outer circumferential surface or end surface of the first end of the second connecting shaft 62 to position the second connecting shaft 62 relative to the inner shaft 12. Figure 1 As shown, when the first connecting shaft 61 is installed in place, the end of the outer shaft 11 abuts against the first connecting positioning shoulder 611, and when the second connecting shaft 62 is installed in place, the end of the inner shaft 12 abuts against the second connecting positioning shoulder 621.

[0049] However, this application is not limited to this. When the dimensions of the outer shaft 11 and the inner shaft 12 are suitable, the first connecting positioning shoulder 611 may also be formed on the outer peripheral surface of the first connecting shaft 61, and the second connecting positioning shoulder 611 may also be formed on the inner peripheral surface of the second connecting shaft 62.

[0050] If there is sufficient internal space in the rotating joint, an additional module positioning shoulder 623 may also be formed on the outer peripheral surface of the first connecting shaft 61. For example, the additional module positioning shoulder 623 can be used to mount a brake module on the outer peripheral surface of the first connecting shaft 61. In one embodiment, the brake module may be mounted between the additional module positioning shoulder 623 and the encoder assembly 30 to brake the outer shaft 11.

[0051] exist Figure 1-4 In the illustrated embodiment, the second connecting shaft 62 is a hollow shaft, with its hollow portion used for passing through the wire harness. Therefore, the second connecting shaft 62 can serve as a wire guide shaft for the joint. If the wire harness in the joint does not need to pass through the second connecting shaft 62, the second connecting shaft 62 can also be a solid shaft. In embodiments of this application, the second connecting shaft 62 may not be used for outputting torque, but only for assisting in measuring the rotational speed of the transmission device's rotating shaft, or as a wire guide shaft.

[0052] Furthermore, a disassembly auxiliary shoulder 622 may be formed on the inner circumferential surface of the second connecting shaft 62. The disassembly auxiliary shoulder 622 is used to assist in the separation operation of the second connecting shaft 62 from the inner shaft 12. Specifically, the second connecting shaft 62 can be separated from the inner shaft 12 by inserting a dedicated disassembly stepped shaft from one side of the first end of the second connecting shaft 62 against the disassembly auxiliary shoulder 622 and pushing the second connecting shaft 62.

[0053] The first connecting shaft 61 can be driven to rotate by a motor of a drive device. It can be used as the drive shaft of a joint, connected to the drive shaft of the joint, or integrated with it. That is, the rotational speed of the first connecting shaft 61 is the rotational speed of the drive shaft of the joint. The second connecting shaft 62 can be driven by a transmission device and connected to the output shaft of the joint or integrated with it. That is, the output of the transmission device can be used as the output shaft of the joint, and the second connecting shaft 62 rotates synchronously with the output shaft of the joint. The rotational speed of the second connecting shaft 62 is the rotational speed of the output shaft of the joint. In the above embodiment, the first connecting shaft 61 can rotate synchronously with the drive shaft of the rotary joint, and the second connecting shaft 62 can rotate synchronously with the output shaft of the rotary joint. However, it should be noted that this application is not limited to this. Where the structure of the drive device allows, the first connecting shaft 61 can rotate synchronously with the output shaft of the rotary joint, and the second connecting shaft 62 can rotate synchronously with the drive shaft of the rotary joint.

[0054] In some embodiments, the output shaft of the joint and the drive shaft of the joint (e.g., the motor shaft for rotating the joint) can be located on opposite sides of the drive device. Figure 1-4 In the illustrated embodiment, the extending directions of the second connecting shaft 62 and the first connecting shaft 61 are the same as the extending directions of the joint's drive shaft (e.g., the joint motor shaft). Furthermore, axially, the second end of the second connecting shaft 62 does not extend beyond the second end of the first connecting shaft 61. The second ends of the first connecting shaft 61 and the second ends of the second connecting shaft 62 are respectively used to mount the disk assemblies 31 and 32 of the encoder assembly, thereby allowing the encoder modules or encoder assemblies mounted on the two connecting shafts to be compactly mounted axially on the same side of the drive unit, which helps to reduce the axial space occupied by the encoder module in the joint. Those skilled in the art will understand that the axial space involved can be necessary clearance space, for example, space reserved to consider heat dissipation, vibration, or wiring issues.

[0055] like Figure 1 As shown, at any position in the axial direction of the first connecting shaft 61 and the second connecting shaft 62, the outer diameter of the second connecting shaft 62 is smaller than the inner diameter of the first connecting shaft 61. Therefore, they are radially spaced apart and do not directly contact each other. Consequently, the rotation of the first connecting shaft 61 and the second connecting shaft 62 is relatively independent; that is, the rotation of the first connecting shaft 61 does not interfere with the rotation of the second connecting shaft 62, and vice versa. Thus, the rotational speed of the first connecting shaft 61 and the rotational speed of the second connecting shaft 62 can respectively represent the rotational speed of the joint's drive shaft and the rotational speed of its output shaft. When the rotational speeds of the first connecting shaft 61 and the second connecting shaft 62 are measured using two encoder assemblies respectively, the actual rotational speeds of the joint's drive shaft and output shaft can be accurately reflected.

[0056] Although Figure 1-4 In the illustrated embodiment, the rotational speed of the first connecting shaft 61 and the rotational speed of the second connecting shaft 62 represent the rotational speed of the joint's drive shaft and the rotational speed of its output shaft, respectively. However, this application is not limited thereto. That is, in the output structure of the drive device, such as the structure of the motor and the transmission device, if permitted, the first connecting shaft 61 can also be arranged to rotate synchronously with the joint's output shaft, while the second connecting shaft 62 can be arranged to rotate synchronously with the joint's drive shaft (e.g., the joint motor shaft).

[0057] Furthermore, as mentioned above, in the embodiments of this application, the transmission ratio of the drive device can be greater than or equal to 1, or less than or equal to 1. That is, depending on the needs, the transmission device can be a speed reducer, a speed increaser, or even a speed changer that simultaneously has both speed increase and speed decrease capabilities. Therefore, the ratio of the rotational speed of the joint's drive shaft to the rotational speed of the joint's output shaft can be greater than or equal to 1, or less than or equal to 1.

[0058] As previously described, the encoder assembly 30 includes a disk assembly and a sensor assembly. The following will refer to... Figures 1 to 4 The mounting structure of the encoder assembly 30 in the joint according to an embodiment of this application is described in detail.

[0059] like Figures 1 to 4 As shown, the encoder assembly 30 includes a first disk assembly 31 mounted on a first connecting shaft 61 and a second disk assembly 32 mounted on a second connecting shaft 62. The first disk assembly 31 includes a first disk 311 and a first mounting bracket 312 for mounting the first disk 311. The first mounting bracket 312 is an annular member with an inner hole, which is fitted and fixed to the second end of the first connecting shaft 61 through the inner hole. To ensure a secure installation, an interference fit connection is suitable between the first mounting bracket 312 and the first connecting shaft 61.

[0060] The outer ring of the first disk 311 can be fixed to the annular portion of the first mounting bracket 312 using threaded fasteners such as screws. Thus, when the first connecting shaft 61 rotates, the first disk assembly 31, consisting of the first mounting bracket 312 and the first disk 311, rotates synchronously with the first connecting shaft 61. That is, the rotational speed of the first disk 311 is the same as the rotational speed of the joint's drive shaft. In a further embodiment, the first connecting shaft 61 and the first mounting bracket 312 can be formed as an integral component.

[0061] The second disk assembly 32 includes a second disk 321 and a second mounting bracket 322 for mounting the second disk 321. The second mounting bracket 312 is an annular member with an inner hole, which is fitted and fixed to the second end of the second connecting shaft 62 through the inner hole. To ensure a secure installation, an interference fit is preferably used between the second mounting bracket 322 and the second connecting shaft 62. The outer ring of the second disk 321 can be fixed to the annular portion of the second mounting bracket 322 using threaded fasteners such as screws. Thus, when the second connecting shaft 62 rotates, the second disk assembly 32, consisting of the second mounting bracket 322 and the second disk 321, rotates synchronously with the second connecting shaft 62. That is, the rotational speed of the second disk 321 is the same as the rotational speed of the joint's output shaft. In a further embodiment, the second connecting shaft 62 and the second mounting bracket 322 can also be formed as an integral component.

[0062] In this embodiment, the distance between the mounting position of the first mounting bracket 312 on the first connecting shaft 61 and the end surface of the first disk 311 is greater than the distance between the position of the second mounting bracket 322 on the second connecting shaft 62 and the end surface of the second disk 321. The first mounting bracket 312 may include a first disk mounting portion, a first connecting shaft mounting portion having an inner hole, and a connecting portion connecting the two. Figure 1 and Figure 2 As shown, the connecting portion can be formed as an inclined portion to reserve installation space for the second mounting bracket 322 in the axial direction, so as to prevent any interference between the first mounting bracket 312 and the second mounting bracket 322 in the axial or radial direction, which would affect the rotational speed of the disk or cause magnetic field interference between the two disks. The inclination angle of the connecting portion can be greater than or equal to 90 degrees. In addition, the connecting portion can also be formed as a curved shape.

[0063] In this embodiment, although the first disk 311 and the second disk 321 are respectively mounted on the first connecting shaft 61 and the second connecting shaft 62 via the first mounting bracket 312 and the second mounting bracket 322, those skilled in the art should understand that, for example, if the inner diameter of the second disk 321 is suitable, it is possible to directly mount the second disk 321 onto the second connecting shaft 62. That is, the method by which the first disk 311 and the second disk 321 are fixedly connected to the first connecting shaft 61 and the second connecting shaft 62 is not limited to the method described above. Any mounting structure that ensures the first disk 311 and the second disk 321 rotate synchronously with the first connecting shaft 61 and the second connecting shaft 62 is permissible.

[0064] Furthermore, the first disk 311 and the second disk 312 are mounted coplanarly, which further reduces the axial space occupied or involved by the encoder assembly 30 in the joint. For example... Figure 1 and Figure 2 As shown, the first disk 311 may be located radially outside the second disk 321, and the first disk 311 and the second disk 321 may be radially spaced apart to avoid magnetic field interference between them, which would cause distortion of the electrical signals received by the corresponding sensor components.

[0065] As previously described, the encoder assembly 30 also includes a first sensor assembly mounted adjacent to the first disk 311 and a second sensor assembly mounted adjacent to the second disk 321. The first sensor assembly is used to detect the rotational movement of the first disk 311, and the second sensor assembly is used to detect the rotational movement of the second disk 321. Although not explicitly shown, both the first and second sensor assemblies are mounted on a PCB circuit board 50, which will be described in detail below. That is, the first sensor assembly (particularly the sensor of the first sensor assembly) may face the first disk 311, and the second sensor assembly (particularly the sensor of the second sensor assembly) may face the second disk 321. The first sensor assembly generates a digital signal of the rotational speed of the first shaft 61 based on the electrical signal generated by the rotation of the first disk 311, and the second sensor assembly generates a digital signal of the rotational speed of the second shaft 62 based on the electrical signal generated by the rotation of the second disk 321. The control device of at least one of the joints, robotic arms, and robots can receive these digital signals from the first and second sensor assemblies to provide feedback control or adjustment control of the joint's drive mechanism as needed, thereby precisely controlling the joint and the specific movement of the robotic arm or robot having that joint.

[0066] In the above embodiment, the first sensor assembly and the second sensor assembly are mounted on the same PCB circuit board 50, which not only improves the integration of the circuit and saves the space occupied and clearance of the PCB circuit board, but also reduces heat dissipation problems, reduces the length of the wiring harness and simplifies the connection of the wiring harness.

[0067] like Figure 1As shown, the PCB circuit board 50 is mounted parallel to the first disk 311 and the second disk 321, and is fixedly connected to one end of the joint housing via a connecting assembly 40. The connecting assembly 40 is located between one end of the joint housing and the PCB circuit board 50, with one end connected to one end of the joint housing and the other end connected to the PCB circuit board 50, maintaining a certain gap between the PCB circuit board 50 and one end of the joint housing. This gap is slightly larger than the designed protrusion length of the first disk assembly 31 and the second disk assembly 32 relative to one end of the joint housing. When both sensor assemblies are mounted on the PCB circuit board 50, it is necessary to ensure that a suitable gap is maintained between the end surfaces of the first disk assembly 31 and the second disk assembly 32 and the sensor assemblies on the PCB circuit board 50, so that the sensor assemblies 31 and 32 can accurately detect the rotational speed of the first disk 311 and the second disk 321. Preferably, the designed protrusion length is greater than the thickness of the disk assembly. In this application, the thickness of the disk assembly can refer to the distance between the disk surface of the disk assembly and the rear surface of its mounting bracket; the disk assembly can be removed by clamping it according to its thickness. In other words, the thickness of a disk assembly refers to the thickness that can be clamped at the outer periphery of the disk assembly. For a disk assembly in this application that includes both a first disk assembly 31 and a second disk assembly 32 arranged coplanarly, the thickness of the disk assembly refers to the thickness of the disk assembly 31 located radially outward.

[0068] When installing the first disk assembly 31 and the second disk assembly 32, firstly, the first connecting shaft 61 is installed onto the outer shaft 11 so that the end of the outer shaft 11 abuts against the first connecting positioning shoulder 611. Then, the second connecting shaft 62 is connected to the inner shaft 12 so that the end of the inner shaft 12 abuts against the second connecting positioning shoulder 621. Next, the inner ring of the bearing 70 is applied with 609 glue and pressed between the first connecting shaft 61 and the second connecting shaft 62. Then, the first disk 311 is installed on the first mounting bracket 312 to form the first disk assembly 31, and the second disk 321 is installed on the second mounting bracket 322 to form the second disk assembly 32. The first disk assembly 31 is fitted onto the first connecting shaft 61, and the second disk assembly 32 is fitted onto the second connecting shaft 62. Then, using methods such as... Figure 2 The disk mounting fixture 14 shown presses two disk assemblies 31 and 32 simultaneously along the axial direction onto two connecting shafts 61 and 62, which are respectively connected to the inner shaft 12 and the outer shaft 11 of the drive device. By using the disk mounting fixture 14 to press two disk assemblies 31 and 32 simultaneously, it can be ensured that the distance from the end surface of the two disks (i.e., the disk surface facing the PCB circuit board 50 or the sensor assembly) to the end surface of the joint housing and the coplanarity of the two disks (i.e., the disk surfaces) meet the requirements.

[0069] After the disk assemblies are installed in place, the disk mounting fixture 14 is removed, and then the PCB circuit board 50 is fixed using the connecting assembly 40 (e.g., fixed to the joint housing or drive unit), and the gap between the PCB circuit board 50 and the end surfaces (i.e., disk surfaces) of the two disks is adjusted. By ensuring that the gap between the PCB circuit board 50 and the end surfaces of the two disks is appropriate, each sensor assembly can accurately detect the change in magnetic field generated by the rotation of the corresponding disk assembly, thereby outputting a digital signal about the rotational speed of the corresponding connecting shaft, thus obtaining the rotational speed information of the drive shaft and output shaft of the rotating joint. After the encoder module is installed in place, as... Figure 1 As shown, the encoder module or encoder assembly can be mounted to extend a predetermined length relative to one end of the joint housing to facilitate subsequent disassembly of the encoder module.

[0070] The connecting assembly 40 may include isolation posts, such as cylindrical or hexagonal isolation posts, wherein each end of each isolation post may be formed with internal or external threads. One end of the isolation post may be threaded to one end of the joint housing, and the other end of the isolation post may be threaded to the PCB circuit board 50. More specifically, one end of the isolation post may be connected to at least one of the end surface, inner wall, or outer wall of one end of the joint housing, while the other end of the isolation post may be threaded to the PCB circuit board 50 by additional screws, bolts, or nuts. When one end of the isolation post is connected to the inner or outer wall of one end of the joint housing, a corresponding inner or outer protrusion may be formed on the inner or outer wall of the joint housing. Through holes or threaded holes may be formed in the inner or outer protrusions for connection. There are at least two connecting assemblies 40, preferably three, four, five, six, or more. The number of connecting assemblies 40 may be determined according to the size of the joint housing, the shape and weight of the PCB circuit board, and the specifications of the isolation posts.

[0071] The connecting assembly 40 is not limited to a separating post with internal or external threads at both ends. For example, the connecting assembly 40 may also include at least one protrusion extending axially from at least one of the inner wall, outer wall, and / or end surface of one end of the joint housing, and a threaded fastener threadedly connected to the protrusion. The protrusion extends a predetermined distance relative to one end of the joint housing and is integrally formed with the joint housing, wherein a threaded hole is formed in the protrusion. The PCB circuit board 50 is connected and fixedly attached to the joint housing by the engagement between the threaded fastener and the protrusion, which allows the PCB circuit board 50 to be fixed to the joint housing at a predetermined distance from one end of the joint housing.

[0072] like Figure 1As shown, the PCB circuit board 50 has a central hole for a cable or wire harness to pass through. The end of the second connecting shaft 62 does not extend into or pass through the PCB circuit board 50, but is axially separated from the PCB circuit board 50 and flush with the disk surface of the disk assembly. As can be seen from the preceding description, the first mounting bracket 312 and the second mounting bracket 322 are located on one side of the first and second disks and are axially connected to them without clearance, while the PCB circuit board 50 is located on the other side of the first and second disks and is axially spaced from them. The compact arrangement of the PCB circuit board and the first and second disk assemblies, respectively mounted on the first connecting shaft 61 and the second connecting shaft 62, effectively reduces the axial space occupied by the encoder module in the rotating joint.

[0073] In one embodiment, the connecting component 40 can be an isolation post, or a protruding post and a threaded fastener. Both types of connecting components can be used simultaneously to connect one end of the PCB circuit board 50 to the joint housing 20 in a joint.

[0074] For ease of installation and removal, the isolation post can be a hexagonal stud with external threads at one end and internal threads at the other. One end of the hexagonal stud can be screwed into the end surface of one end of the joint housing, while the other end can be secured with a through-hole screw on the PCB circuit board 50. By changing the screwing depth of one end of the hexagonal stud, the distance between the PCB circuit board 50 and one end of the joint housing can be adjusted to regulate the clearance between the disk assembly and the sensor assembly.

[0075] In the above embodiment, when disassembling the encoder module, the PCB circuit board 50 can be removed first, and then the first disk assembly 31 and the second disk assembly 32 can be simultaneously removed from the first connecting shaft 61 and the second connecting shaft 62 using a disk removal jig. Then, the second connecting shaft 62 and the bearing 70 can be removed simultaneously using the aforementioned stepped shaft, and finally the first connecting shaft 61 can be removed.

[0076] In the embodiments of this application, steps (i.e., shoulders) for mounting bearings are formed at the ends of the first and second connecting shafts, adjacent to the disk mounting bracket. This ensures the coaxiality of the two slender shafts extending from the drive device in the joint housing and provides rigid support for these two shafts, while not hindering their independent rotation. This ensures concentric mounting of the encoder module with the drive shaft and output shaft of the rotating joint, avoiding asymmetry or angular errors. The above structure also improves the robustness of the encoder module to shocks and vibrations. Furthermore, the end surfaces of the second ends of the two connecting shafts are flush with the corresponding disk surfaces, minimizing the length of the slender shafts, reducing the manufacturing difficulty of the product, and simplifying the installation and calibration of the encoder module.

[0077] In addition, the bearings, input disk brackets, and output disk brackets of the encoder module can all be installed using a combination of stepped shaft positioning and interference fit with adhesive application, which simplifies the assembly structure of the encoder module and further facilitates installation and disassembly.

[0078] In the embodiments of this application, the specific position of one end of the joint housing to which the connecting component is connected can be reasonably selected based on the size and structure of the joint housing, the size and structure of the PCB circuit board, and the size of the first disk component in the encoder assembly, and is not limited to a certain fixed position.

[0079] According to at least one embodiment of this application, the connection method between the PCB circuit board and the joint housing not only facilitates the installation and disassembly of the PCB circuit board and the encoder assembly, but also facilitates the adjustment of the gap between the sensor assembly on the PCB circuit board and the end surface of the disk in the encoder assembly, further improving the assembly efficiency of the joint.

[0080] Furthermore, the input and output disks (i.e., the first and second disks) in the encoder module of the joint are arranged on the same end face and use only one PCB circuit board. This makes full use of the radial space, greatly saves the axial space of the joint, improves system integration, and contributes to the miniaturization of the product. At the same time, the two disks can be installed, adjusted, removed, and used with the same tooling fixture simultaneously, which improves installation accuracy and efficiency.

[0081] Furthermore, by centrally arranging the encoder modules for the drive shaft (e.g., the joint motor shaft) and output shaft of the joint at one end of the joint housing, the adjustment of the gap between the disk and the sensor on the PCB circuit board is further simplified (because the gap requirement between the disk and the sensor is very strict). This arrangement allows for precise press-fitting using a disk mounting fixture, reducing the steps involved in gap adjustment. Such an encoder module structure is more suitable for harsh industrial environments with extreme temperatures, humidity, and particulate contamination.

[0082] In the description of this application, it should be understood that the terms "center", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0083] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0084] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0085] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0086] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "up," "down," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0087] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. An encoder module for a rotary joint, the rotary joint including a drive device having an inner shaft extending toward the same side and an outer shaft surrounding the inner shaft and radially spaced from the inner shaft, characterized in that, The encoder module includes: A first connecting shaft has a first end and a second end, wherein the first end of the first connecting shaft is used for detachably fixed connection to the end of the outer shaft; The second connecting shaft has a first end and a second end, the first end of the second connecting shaft being used for detachably fixed connection with the inner shaft; The first disk assembly is fixed to the first connecting shaft; The second disk assembly is fixed to the second connecting shaft; A first sensor assembly is arranged adjacent to the first disk assembly; The second sensor assembly is arranged adjacent to the second disk assembly. Wherein, the disk surfaces of the first disk assembly and the second disk assembly are arranged to be coplanar and radially separated by at least a predetermined distance. The encoder module further includes a bearing installed between the first connecting shaft and the second connecting shaft. The first connecting shaft is a hollow shaft with a first bearing positioning shoulder formed on its inner circumferential surface, and the second connecting shaft has a second bearing positioning shoulder formed on its outer circumferential surface. Wherein, the end surface of the second end of the first connecting shaft is flush with the outer end surface of the bearing, the end surface of the second end of the second connecting shaft is flush with the disk surface of the first disk assembly and the disk surface of the second disk assembly, the second end of the first connecting shaft does not extend beyond the second end of the second connecting shaft, and at any position in the axial direction of the first connecting shaft and the second connecting shaft, the outer diameter of the second connecting shaft is smaller than the inner diameter of the first connecting shaft. Wherein, a second connecting positioning shoulder is formed on the outer peripheral surface of the second connecting shaft or on the end surface of the first end, for positioning the second connecting shaft relative to the inner shaft in the mounting position, and / or Wherein, the second connecting shaft is a hollow shaft, and a second connecting positioning shoulder and / or a disassembly auxiliary shoulder are formed on the inner circumferential surface of the second connecting shaft. The second connecting positioning shoulder is used to position the second connecting shaft relative to the inner shaft, and the disassembly auxiliary shoulder is used to separate the second connecting shaft from the inner shaft. Wherein, a first connecting positioning shoulder is formed on the inner or outer peripheral surface of the first end of the first connecting shaft, for positioning the first connecting shaft relative to the outer shaft.

2. The encoder module as described in claim 1, characterized in that, An additional module positioning shoulder is formed on the outer peripheral surface of the first connecting shaft.

3. The encoder module as described in claim 1, wherein, The bearing is bonded to at least one of the first connecting shaft and the second connecting shaft by an adhesive.

4. The encoder module as described in claim 1, wherein, The bearing is a deep groove ball bearing, and the inner ring of the bearing is bonded to the second connecting shaft with an adhesive.

5. The encoder module as described in claim 1, wherein, The encoder module structure also includes a PCB circuit board on which the first sensor assembly and the second sensor assembly are mounted, wherein the PCB circuit board is parallel to and spaced apart from the disk surfaces of the first disk assembly and the second disk assembly.

6. The encoder module as described in claim 1, wherein, The first disk assembly includes a first disk and a first mounting bracket supporting the first disk, the first mounting bracket being mounted on the second end of the first connecting shaft.

7. The encoder module as described in claim 6, wherein, The second disk assembly includes a second disk and a second mounting bracket supporting the second disk, the second mounting bracket being mounted on the second end of the second connecting shaft.

8. The encoder module as described in claim 7, wherein, The first mounting bracket and the second mounting bracket are spaced apart in both the axial and radial directions, wherein the first mounting bracket and the first connecting shaft are formed separately or integrally, and the second mounting bracket and the second connecting shaft are formed separately or integrally.

9. The encoder module as described in claim 7, wherein, The outer and / or inner rings of the first disk are fixed to the first mounting bracket, and the outer and / or inner rings of the second disk are fixed to the second mounting bracket.

10. A rotary joint for a robot, comprising a joint housing, a drive as claimed in claim 1, and an encoder module for the rotary joint as claimed in any one of claims 1-9.

11. The rotary joint for a robot as described in claim 10, wherein, The drive device includes a motor and a transmission device driven by the motor, wherein the motor drives one of the inner shaft and the outer shaft, and the transmission device drives the other of the outer shaft and the inner shaft.

12. The rotary joint for a robot as described in claim 10, wherein, The drive unit is installed inside the joint housing, and the encoder module extends a predetermined length relative to one end of the joint housing.

13. The rotary joint for a robot as described in claim 10, wherein, The rotating joint also includes a control device for adjusting the operation of the drive device based on the signals output by the first sensor assembly and the second sensor assembly.

14. A robotic arm for a robot, comprising at least one rotary joint for a robot as described in any one of claims 10 to 13.

15. A robot comprising at least one rotary joint for a robot as described in any one of claims 10 to 13.

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